Programming such as television programs is, in many cases, produced with variable loudness and wide dynamic range to convey emotion or a level of excitement in a given scene. For example, a movie may include a scene with the subtle chirping of a cricket and another scene with the blasting sound of a shooting cannon. Interstitial material such as commercial advertisements, on the other hand, is very often intended to convey a coherent message, and is, thus, often produced at a constant loudness, narrow dynamic range, or both.
Conventionally, annoying disturbances occurred at the point of transition between the programming and the interstitial material. This is commonly known as the “loud commercial problem.” In some cases, even when switching between programming and interstitial material that had matched average loudness and dynamic range, the loudness of the programming may decrease for artistic reasons for a period of time, possibly enough time to cause users to increase the volume of the audio. When this quieter-than-average section of the program switched to interstitial material that matched the original average loudness of the programming, the interstitial material may be too loud due to the increase in volume by the user.
Conventionally, processes addressing the loud commercial problem modified the audio itself, thus making the processes irreversible. However, not all viewers may desire to have the programming audio changed in such a way.
Conventionally, techniques have focused on managing average loudness of one segment versus another segment, ignoring short term changes at boundary points. Other conventional techniques essentially change all of the audio at all times, differing little from a standard dynamic range controller that may be found in analog broadcast.